Note that Large Object File Descriptors are only valid within a single
database transaction, so if you are interested in using anything beyond
loCreat, loCreate, and loUnlink, you will need to run the entire
sequence of functions in a transaction. As loImport and loExport
are simply C functions that call loCreat, loOpen, loRead, and
loWrite, and do not perform any transaction handling themselves,
they also need to be wrapped in an explicit transaction.